This Sleek Planck Keyboard Solves a Very Niche Problem
Der-B built this unique mechanical Planck keyboard that has three USB output ports.
Dual monitors are a slippery slope and before you know it, you’ll want two completely independent computers running at the same time. Maybe one has Linux installed and the other runs Windows, or one is for work tasks while the other is for personal stuff. Whatever the case, you probably don’t want to have two keyboard and two mice sitting on your desk — that’d be needlessly redundant and the positions would be uncomfortable. Der-B wanted a Planck keyboard that could easily switch between computers, so he designed this sleek beauty.
Users that want to switch between computers can, of course, use KVM (keyboard, video, mouse) switches — that is their entire purpose. There is also software that can achieve the same result virtually if the computers are connected to a shared network. But a KVM switch is one more device with messy cables to setup and the software isn’t always an option. Der-B’s mechanical USB-multiplexing Planck keyboard keeps everything very tidy and doesn’t need any special software at all. Just connect USB cables from the keyboard to the computers and it can switch between them as necessary.
The Planck layout isn’t the most ergonomic option, but it is the most compact. Der-B’s design has just 48 keys arranged in an ortholinear grid. It uses low-profile Cherry MX mechanical key switches, with 3D-printed key caps to match the 3D-printed frame. It really isn’t possible to make a mechanical keyboard like this much smaller while still utilizing full-size keys.
A custom PCB contains two important components: a Microchip ATmega32U4 microcontroller and an Onsemi FSUSB63 3:1 USB 2.0 multiplexing switch IC. That chip physically switches USB connections between the one input (coming from the AVR chip) and the three outputs (going to the computers). As far as the computers know, the user is unplugging the USB cable from one and plugging it into the other.
Der-B did find some problems with this design, such as the shape of the key caps making it difficult to type accurately. And the 48-key Planck layout in general is difficult to learn. But this keyboard does work and does solve the problem it was meant to.